Page 403 of 464

4038-2. Steps to take in an emergency
MIRAI_OM_USA_OM62023U
8
When trouble arises
Close the exclusive jump starting terminal cover, reinstall the motor
cover and the fuse box cover to its original position.
Once the fuel cell system starts, have the vehicle inspected at your
Toyota dealer as soon as possible.
■ Starting the fuel cell system when the 12-volt battery is discharged
The fuel cell system cannot be started by push-starting.
■ To prevent 12-volt battery discharge
●Turn off the headlights and the audio system while the fuel cell system is off.
● Turn off any unnecessary electrical components when the vehicle is running
at a low speed for an extended period, such as in heavy traffic.
■ Charging the 12-volt battery
The electricity stored in the 12-volt battery will discharge gradually even when
the vehicle is not in use, due to natural discharge and the draining effects of
certain electrical appliances. If the vehicle is left for a long time, the 12-volt
battery may discharge, and the fuel cell system may be unable to start. \
(The
12-volt battery recharges automatically while the fuel cell system is operat-
ing.)
■ When the 12-volt battery is removed or discharged
●In some cases, it may not be possible to unlock the doors using the smart
key system when the 12-volt battery is discharged. Use the wireless remote
control or the mechanical key to lock or unlock the doors.
● The fuel cell system may not start on the first attempt after the 12-volt bat-
tery has recharged but will start normally after the second attempt. This is
not a malfunction.
● The power switch mode is memorized by the vehicle. When the 12-volt bat-
tery is reconnected, the system will return to the mode it was in before the
12-volt battery was discharged. Before disconnecting the 12-volt battery,
turn the power switch off.
If you are unsure what mode the power switch was in before the 12-volt bat-
tery discharged, be especially careful when reconnecting the 12-volt battery.
● If the 12-volt battery is depleted with the shift position in P, it will not be pos-
sible to shift the shift position other than P. In this case, the vehicle cannot
be towed without lifting both front wheels because the front wheels are
locked by the parking lock. ( →P. 363)
● When the 12-volt battery is reconnected, start the fuel cell system, depress
the brake pedal, and confirm that it is possible to shift into each shift posi-
tion.
● Make sure that the key is not inside the vehicle when recharging or replac-
ing the 12-volt battery. The key may be locked in the vehicle if the alarm is
activated. ( →P. 75)
9
Page 404 of 464

4048-2. Steps to take in an emergency
MIRAI_OM_USA_OM62023U■
When exchanging the 12-volt battery
Use a Central Degassing type 12-volt battery (Japanese Industrial Stan-
dards). Also, use 12-volt batteries with case sizes similar to one prior the
exchange and an equivalent 20 hour rate capacity (20HR) or greater.
• If the sizes differ, the 12-volt battery cannot be properly secured.
• If the 20 hour rate capacity is low, even if the time period where the vehicle
is not used is a short time, the 12-volt battery may discharge and fuel cell
system may not be able to start.
For details, consult your Toyota dealer.
WARNING
■ Avoiding 12-volt battery fires or explosions
Observe the following precautions to prevent accidentally igniting the flam-
mable gas that may be emitted from the 12-volt battery:
● Make sure each jumper cable is connected to the correct terminal and that
it is not unintentionally in contact with any other than the intended terminal.
● Do not allow the other end of the jumper cable connected to the “+” termi-
nal to come into contact with any other parts or metal surfaces in the area,
such as brackets or unpainted metal.
● Do not allow the + and - clamps of the jumper cables to come into contact
with each other.
● Do not smoke, use matches, cigarette lighters or allow open flame near
the 12-volt battery.
■ 12-volt battery precautions
The 12-volt battery contains poisonous and corrosive acidic electrolyte,
while related parts contain lead and lead compounds. Observe the following
precautions when handling the 12-volt battery:
● When working with the 12-volt battery, always wear safety glasses and
take care not to allow any 12-volt battery fluids (acid) to come into contact
with skin, clothing or the vehicle body.
● Do not lean over the 12-volt battery.
● In the event that 12-volt battery fluid comes into contact with the skin or
eyes, immediately wash the affected area with water and seek medical
attention.
Place a wet sponge or cloth over the affected area until medical attention
can be received.
● Always wash your hands after handling the 12-volt battery support, termi-
nals, and other battery-related parts.
● Do not allow children near the 12-volt battery.
Page 405 of 464

4058-2. Steps to take in an emergency
MIRAI_OM_USA_OM62023U
8
When trouble arises
WARNING
■After recharging the 12-volt battery
Have the 12-volt battery inspected at your Toyota dealer as soon as possi-
ble.
If the 12-volt battery is deteriorating, continued use may cause the 12-volt
battery to emit a malodorous gas, which may be detrimental to the health of
passengers.
■ When exchanging the 12-volt battery
After exchanging, securely attach the exhaust hose and exhaust hole plug
to the exhaust hole of the exchanged 12-volt battery. If not properly
installed, gases (hydrogen) may leak into the vehicle interior, and there is
the possible danger of the gas igniting and exploding.
■ When replacing the 12-volt battery
→ P. 330
NOTICE
■ To prevent damaging the vehicle
The exclusive jump starting terminal is to be used when charging the 12-volt
battery from another vehicle in an emergency. It cannot be used to jump
start another vehicle.
■ When handling jumper cables
When connecting the jumper cables, ensure that they do not become entan-
gled in the cooling fans.
Page 418 of 464
4189-1. Specifications
MIRAI_OM_USA_OM62023U*: This is the maximum possible fill amount. The actual fuel amount achieved
at hydrogen stations may be lower due to station capacity or station set-
tings.
Fuel
Fuel type Compressed hydrogen gas
Nominal working
pressure10150 psi (70 MPa, 714 kgf/cm2, 700 bar)
Hydrogen tanks’ fuel
capacity
(Reference)32.3 gal. (122.4 L, 26.9 Imp.gal.)
(Approximately 11.0 lb. [5 kg]
*)
Electric motor (traction motor)
Type
Permanent magnet synchronous motor
Maximum output 113 kW
Maximum torque 247 ft•lbf (335 N•m, 34.2 kgf•m)
Traction battery
TypeNickel-metal hydride battery
Voltage7.2 V/module
Capacity 6.5 Ah (3HR)
Quantity34 modules
Overall voltage 244.8 V
Page 420 of 464

4209-1. Specifications
MIRAI_OM_USA_OM62023U
*: The fluid capacity is a reference quantity. If replacement is necessary, contact your Toyota dealer.
*1: Minimum pedal clearance when depressed with a force of 44.1 lbf (196 N,20.0 kgf) while the fuel cell system is operating
*2: Parking brake pedal travel when depressed with a force of 67.5 lbf (300 N,31.0 kgf).
Electrical system
12-volt battery
Open voltage at
68° F (20 °C):12.6 ⎯ 12.8 V Fully charged
12.2 ⎯ 12.4 V Half charged
11.8 ⎯ 12.0 V Discharged
(Voltage checked 20 minutes after the fuel cell
system and all lights are turned off)
Charging rates5 A max.
Transmission
Fluid capacity*4.4 qt. (4.2 L, 3.7 Imp.qt.)
Fluid type Toyota Genuine ATF WS
NOTICE
■ Transmission fluid type
Using transmission fluid other than “Toyota Genuine ATF WS” may ulti-
mately damage the transmission of your vehicle.
Brakes
Pedal clearance*12.95 in. (75 mm) Min.
Pedal free play 0.04 ⎯ 0.24 in. (1 ⎯ 6 mm)
Brake pad wear limit0.04 in. (1.0 mm)
Parking brake lining wear limit0.04 in. (1.0 mm)
Parking brake pedal travel*27⎯ 10 clicks
Fluid type SAE J1703 or FMVSS No.116 DOT 3
Page 429 of 464

4299-1. Specifications
MIRAI_OM_USA_OM62023U
9
Vehicle specifications
Production options
weight
The combined weight of installed regular pro-
duction options weighing over 5 lb. (2.3 kg) in
excess of the standard items which they
replace, not previously considered in curb
weight or accessory weight, including heavy
duty brakes, ride levelers, roof rack, heavy
duty 12-volt battery, and special trim
Rim
A metal support for a tire or a tire and tube
assembly upon which the tire beads are
seated
Rim diameter
(Wheel diameter)Nominal diameter of the bead seat
Rim size designationRim diameter and width
Rim type designationThe industry manufacturer’s designation for a
rim by style or code
Rim widthNominal distance between rim flanges
Vehicle capacity
weight (Total load
capacity)The rated cargo and luggage load plus 150 lb.
(68 kg) times the vehicle’s designated seating
capacity
Vehicle maximum load
on the tire
The load on an individual tire that is deter-
mined by distributing to each axle its share of
the maximum loaded vehicle weight, and
dividing by two
Vehicle normal load on
the tire
The load on an individual tire that is deter-
mined by distributing to each axle its share of
curb weight, accessory weight, and normal
occupant weight (distributed in accordance
with Table 1
* below), and dividing by two
Weather sideThe surface area of the rim not covered by the
inflated tire
Bead
The part of the tire that is made of steel wires,
wrapped or reinforced by ply cords and that is
shaped to fit the rim
Bead separationA breakdown of the bond between compo-
nents in the bead
Tire related termMeaning
Page 441 of 464

4419-2. Customization
MIRAI_OM_USA_OM62023U
9
Vehicle specifications
■Vehicle customization
●When the speed linked door locking function and shift position linked door
locking function are both on, the door lock operates as follows.
• When shifting the shift position to any position other than P, all the doors
will be locked.
• If the vehicle is started with all the doors locked, the speed linked door locking function would not operate.
• If the vehicle is started with any door unlocked, the speed linked door locking function will operate.
● When the smart key system is off, smart door unlocking cannot be custom-
ized.
● When the doors remain closed after unlocking the doors and the automatic
door lock function is activated, the signals will be generated in accordance
with the operation signal (buzzer) and the operation signal (emergency
flashers) settings.
■ In the following situations, customize mode in which the settings can be
changed through the mu lti-information display will automatically be
turned off.
● A warning message appears after the customize mode screen is displayed.
● The vehicle begins to move while the customize mode screen is displayed.
NOTICE
■During customization
To prevent 12-volt battery discharge, ensure that the fuel cell system is
operating while customizing features.
Page 442 of 464
4429-3. Items to initialize
MIRAI_OM_USA_OM62023U
Items to initialize
The following items must be initialized for normal system opera-
tion after such cases as the 12-volt battery being reconnected,
or maintenance being performed on the vehicle:
ItemWhen to initializeReference
Power windowWhen functioning abnormallyP. 155
Ion filterAfter changing the ion filterP. 439